The present invention relates to a method for cutting a mother rod lens and to a lens block for supporting a mother rod lens. More particularly, the present invention relates to a method for cutting a mother rod lens, which has a predetermined gradient index, into rod lenses having predetermined lengths.
In the prior art, to manufacture a gradient index rod lens, an elongated mother rod lens having a predetermined gradient index is cut into rod lenses having a predetermined length in accordance with the purpose of usage. Each end surface of a cut rod lens must be formed at a predetermined angle relative to the optical axis of the rod lens. The end surface of the rod lens may be formed so that it is basically perpendicular to the optical axis of the rod lens. Alternatively, the end surface of the rod lens may be inclined relative to the optical axis to decrease reflection loss.
Further, in the prior art, a single mother rod lens is cut to form rod lenses, which have predetermined lengths, one at a time. Therefore, the manufacturing efficiency of the rod lens is low. Further, if the accuracy of perpendicularity between the optical axis of the mother rod lens and the cut surface of the rod lens is low, the optical capabilities of the rod lens may decrease and the difference in lens characteristic between rod lenses may increase. This may decrease the yield of the rod lenses.
It is an object of the present invention to provide a method for cutting a mother rod lens and a lens block for supporting a mother rod lens that increases manufacturing efficiency and increases yield through highly accurate cutting.
To achieve the above object, the present invention provides a method for cutting a plurality of mother rod lenses having a predetermined gradient index with a cutter. The method includes arranging the mother rod lenses, each having an optical axis, such that the optical axes of the mother rod lenses are parallel to one another, and forming a lens block for holding the mother rod lenses. The lens block has a first side surface and a second side surface. The first and second side surfaces are arranged parallel to the optical axes and at a predetermined angle with respect to each other. The method further includes arranging the lens block at a predetermined position, emitting laser beams respectively toward the first and second side surfaces, receiving reflection lights of the laser beams reflected by the first and second side surfaces with first and second screens, respectively, adjusting the perpendicularity of the first side surface relative to a predetermined cutting surface of the cutter such that the reflection light of the first side surface hits a first base position on the first screen, adjusting the perpendicularity of the second side surface relative to the predetermined cutting surface such that the reflection light of the second side surface hits a second base position on the second screen, and cutting the lens block and the mother rod lenses with the cutter to produce a plurality of rod lenses having a predetermined length.
A further perspective of the present invention is a method for cutting a plurality of mother rod lenses having a predetermined gradient index with a cutter. The method includes arranging the mother rod lenses, each having an optical axis, such that the optical axes of the mother rod lenses are parallel to one another, and forming a lens block for holding the mother rod lenses. The lens block has an outer surface parallel to the optical axes. A first flat surface reflection body and a second flat surface reflection body are arranged on the outer surface separated from each other by a predetermined distance. The method further includes arranging the lens block at a predetermined position, emitting laser beams respectively toward the first and second flat surface reflection bodies, receiving reflection lights of the laser beams reflected by the first and second flat surface reflection bodies with first and second screens, respectively, adjusting the perpendicularity of the first flat surface reflection body relative to a predetermined cutting surface of the cutter such that the reflection light of the first flat surface reflection body hits a first base position on the first screen, adjusting the perpendicularity of the second flat surface reflection body relative to the predetermined cutting surface such that the reflection light of the second flat surface reflection body hits a second base position on the second screen, and cutting the lens block and the mother rod lenses with the cutter to produce a plurality of rod lenses having a predetermined length.
A further perspective of the present invention is a lens block for holding a plurality of mother rod lenses having a predetermined gradient index to cut the mother rod lenses with a cutter. The lens block includes a holding frame for holding the mother rod lenses, each having an optical axis, such that the optical axes of the mother rod lenses are parallel to one another. The holding frame has two side surfaces arranged parallel to the optical axes and at a predetermined angle with respect to each other. The holding frame and the mother rod lenses are integrated with each other by a resin.
A further perspective of the present invention is a lens block for holding a plurality of mother rod lenses having a predetermined gradient index to cut the mother rod lenses with a cutter. The lens block includes a holding frame for holding the mother rod lenses, each having an optical axis, such that the optical axes of the mother rod lenses are parallel to one another. The holding frame has an outer surface parallel to the optical axes. The holding frame and the mother rod lenses are integrated with each other by a resin.
A further perspective of the present invention is a lens block for holding a plurality of mother rod lenses having a predetermined gradient index to cut the mother rod lenses with a cutter. The lens block includes a plurality of cylindrical dummy glass rods, each having a center axis, and a holding frame for holding the dummy glass rods such that the center axes of the mother rod lenses are parallel to one another. The holding frame has two side surfaces arranged parallel to the center axes and at a predetermined angle with respect to each other. The mother rod lenses each have a diameter smaller than the diameter of the dummy glass rods. The mother rod lenses are held between the dummy glass rods and the holding frame such that the optical axes of the mother rod lenses are parallel to one another. The holding frame, the dummy glass rods, and the mother rod lenses are integrated with each other by a resin.
A further perspective of the present invention is a lens block for holding a plurality of mother rod lenses having a predetermined gradient index to cut the mother rod lenses with a cutter. The lens block includes a plurality of cylindrical dummy glass rods, each having a center axis, and a holding frame for holding the dummy glass rods such that the center axes of the mother rod lenses are parallel to one another. The holding frame has an outer surface parallel to the center axes. The mother rod lenses each have a diameter smaller than the diameter of the dummy glass rods. The mother rod lens is held between the dummy glass rods and the holding frame such that the optical axes of the mother rod lenses are parallel to one another. The holding frame, the dummy glass rods, and the mother rod lenses are integrated with each other by a resin.
A further perspective of the present invention is a cutting apparatus for cutting a plurality of mother rod lenses held by a lens block. The lens block has a first side surface and a second side surface arranged at a predetermined angle relative to each other. The apparatus includes a cutting machine for cutting the lens block along a predetermined cutting surface. A laser beam source emits laser beams toward the first and second side surfaces. A first screen and a second screen receive reflection lights of the laser beams reflected by the first and second side surfaces, respectively. The first screen has a first base line hit by the reflection light of the laser beam reflected by the first side surface when the first side surface is perpendicular to the predetermined cutting surface. The second screen has a second base line hit by the reflection light of the laser beam reflected by the second side surface when the second side surface is perpendicular to the predetermined cutting surface.
A further perspective of the present invention is a cutting apparatus for cutting a plurality of mother rod lenses held by a lens block. The lens block has an outer surface including a first flat surface reflection body and a second flat surface reflection body separated from each other by a predetermined distance. The apparatus includes a cutting machine for cutting the lens block along a predetermined cutting surface. A laser beam source emits laser beams toward a first side surface and a second side surface. A first screen and a second screen receive reflection lights of the laser beams are reflected by the first and second flat surface reflection bodies, respectively. The first screen has a first base line hit by the reflection light of the laser beam reflected by the first flat surface reflection body when the first flat surface reflection body is perpendicular to the predetermined cutting surface. The second screen has a second base line hit by the reflection light of the laser beam reflected by the second flat surface reflection body when the second flat surface reflection body is perpendicular to the predetermined cutting surface.
A further perspective of the present invention is a method for positioning a lens block holding a plurality of mother rod lenses to cut a plurality of mother rod lenses with a cutter. The lens block includes a holding frame for holding the mother rod lenses, each having an optical axis, such that the optical axes of the mother rod lenses are parallel to one another. The holding frame includes a first side surface and a second side surface arranged parallel to the optical axes and at a predetermined angle relative to each other. The method includes arranging the lens block at a predetermined position, emitting laser beams respectively toward the first and second side surfaces, receiving reflection lights of the laser beams reflected by the first and second side surfaces with first and second screens, respectively, adjusting the perpendicularity of the first side surface relative to a predetermined cutting surface of the cutter such that the reflection light of the first side surface hits a first base position on the first screen, and adjusting the perpendicularity of the second side surface relative to the predetermined cutting surface such that the reflection light of the second side surface hits a second base position on the second screen.
Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.